The invention relates to a process for providing markings or printing on free outer surfaces of packs by means of a printing unit, in particular for providing codings on (cuboidal) cigarette packs by means of a laser coder, the printing unit/the laser coder being positioned in a stationary manner alongside an endless conveyor for the packs. The invention also relates to an apparatus for carrying out the process.
The provision of informative printing and/or codings is gaining increasing importance, in particular for cigarette packs. It is important to integrate the process of printing into the working process of the packaging machine. In this respect, laser printers or laser coders have provided the best results so far. The printing- or code-bearing surface on the outside of the cigarette pack is provided with a coating which is partially removed by the laser coder.
The object of the invention is for the provision of markings or codings on (cigarette) packs to be rendered such that the process and apparatus are integrated in the operating process of the packaging machine and do not require any separate measures.
In order to achieve this object, the process according to the invention is characterized in that the packs are moved past by way of an at least partially free outer surface of the pack, said outer surface being directed towards the printing unit/laser coder and not covered by the endless conveyor, and in that the printing or coding is provided on the free outer surface, or on the free part of the outer surface, of the pack during the conveying movement or during a temporary standstill of the pack.
According to the invention, the packs are transported such that one side of the pack not gripped or covered by the conveying elements is facing the printer or laser coder. Particularly advantageous is the transport of cigarette packs in pack groups, with the pack surfaces in the region of a station facing the laser coder, which simultaneously provides printing or coding to a plurality of packs in the region of the surface concerned. Here measures are provided for the exact positioning of the packs and surfaces to be printed. The conveyor for the cigarette pack can be a drying turret with pockets for accommodating a group of packs each, whose end surfaces are directed radially outward and exposed for printing.
As an alternative, packs can be transported by belt conveyors, with printing being provided to pack surfaces which lie transverse to the pack surfaces gripped by the belt conveyors.